Typically the goals of ergonomic research are one or more of the following: establish a (causal) link between hazards and health outcomes; characterize dose-response relationships between hazards and health outcomes; identify exposure thresholds for hazards; or demonstrate efficacy of interventions. Efforts persist towards all these goals, in continued attempts to understand the etiology of musculoskeletal injuries. Yet, the etiology of work-related musculoskeletal disorders (WRMSDs) remains unclear. In fact, the work- related-ness of musculoskeletal disorders remains a contentious issue. More recently, multifactorial theories for their etiology have been proposed. Yet few ergonomics research studies adequately address the multiple facets of ergonomics: biomechanics, psychosocial factors, work organization, and personal attributes. Some facets are either ignored or poorly assessed. This may lead to incorrect conclusions about the strengths of their effects, and the validity of benchmark design criteria that may be proposed based on a study's results. Specific aims of the project are development and application of a comprehensive assessment methodology for characterizing the work-worker system from an ergonomics perspective. The methodology will consist of several standardized tools (questionnaire, work measurement protocols, and biomechanical assessment). The questionnaire provides qualitative information on the worker, work, and workplace (demographics and psychosocial perspectives, work organization and job design). Work measurement protocols supply quantitative temporal information and qualitative biomechanical data. Biomechanical assessment provides a view of the internal activity necessary to carry out activities observed in the workplace. Products of the assessments will be multi-dimensional work and worker profiles. The worker profile will characterize the worker's interaction with his or her work (personal attributes, psychosocial perspectives, demographics, work history, and health history and status). The work profile will characterize physical and administrative work elements. Together the profiles will be used to identify associations between worker attributes and perceptions, worker health outcomes (musculoskeletal impairment and other strains), and work profiles. The methodology will be applied to mobile computing, an emerging area of office ergonomics. The long term objective of this line of research is development of a predictive model of work-related musculoskeletal impairment, that includes physical, psychosocial, work organization and personal factors, and has generalized applicability across job types for use in research from initial exploration to intervention demonstration efforts.